Help with TCollection etc

[John Gallagher]

I'm writing a component descended from a TPanel (Actually its a Raize
TRzPanel, but that shouldn't be relevent). The component will contain a
collection TButtons (TRzButtons).

I've implemented this using TCollection & TCollectionItem descendants.

Everything appears ok so far, except that I cannot assign an OnClick event
to the buttons within the IDE object inspector.

When I try this, I get "Cannot create a method for an unnamed component".

Any suggestions as to how to fix this ?

My source code is below :

unit BtnPanel;

interface

uses
SysUtils, Classes, RzPanel, RzButton;

type
TBtnPanel = class;

TBtnItem = class(TCollectionItem)
private
{ Private declarations }
FButton:TRzButton;
procedure SetCaption(Value:string);
function GetCaption:string;
procedure SetName(Value:string);
function GetName:string;
procedure SetOnClick(Value:TNotifyEvent);
function GetOnClick:TNotifyEvent;

protected
{ Protected declarations }

public
{ Public declarations }
constructor Create(Collection:TCollection); override;
destructor Destroy; override;
procedure Assign(Source:TPersistent); override;

published
{ Published declarations }
property Name:string read GetName write SetName;
property Caption:string read GetCaption write SetCaption;
property OnClick:TNotifyEvent read GetOnClick write SetOnClick;
end;

TBtns = class(TCollection)
private
{ Private declarations }
FPanel:TBtnPanel;
function GetItem(Index: Integer): TBtnItem;
procedure SetItem(Index: Integer; Value: TBtnItem);

protected
{ Protected declarations }
procedure Update(Item:TCollectionItem); override;

public
{ Public declarations }
constructor Create(Panel: TBtnPanel);
function Add:TBtnItem;
property Items[Index:integer]:TBtnItem read GetItem write SetItem;
default;

published
{ Published declarations }
end;

TBtnPanel = class(TRzPanel)
private
{ Private declarations }
FBtns : TBtns;
procedure SetBtns(Value:TBtns);

protected
{ Protected declarations }

public
{ Public declarations }
constructor Create(AOwner:TComponent); override;
destructor Destroy; override;

published
{ Published declarations }
property Btns:TBtns read FBtns write SetBtns;
end;

procedure Register;

implementation

{ TBtnItem }

procedure TBtnItem.Assign(Source: TPersistent);
begin
//
end;

constructor TBtnItem.Create(Collection: TCollection);
begin
inherited Create(Collection);
FButton := TRzButton.Create(TBtns(Collection).FPanel);
FButton.Parent := TBtns(Collection).FPanel;
end;

destructor TBtnItem.Destroy;
begin
FButton.Free;
inherited Destroy;
end;

function TBtnItem.GetCaption: string;
begin
Result := FButton.Caption;
end;

function TBtnItem.GetName: string;
begin
Result := FButton.Name;
end;

function TBtnItem.GetOnClick: TNotifyEvent;
begin
Result := FButton.OnClick;
end;

procedure TBtnItem.SetCaption(Value: string);
begin
FButton.Caption := Value;
end;

procedure TBtnItem.SetName(Value: string);
begin
FButton.Name := Value;
end;

procedure TBtnItem.SetOnClick(Value: TNotifyEvent);
begin
FButton.OnClick := Value;
end;

{ TBtns }

function TBtns.Add: TBtnItem;
begin
Result := TBtnItem(inherited Add);
end;

constructor TBtns.Create(Panel: TBtnPanel);
begin
inherited Create(TBtnItem);
FPanel := Panel;
end;

function TBtns.GetItem(Index: Integer): TBtnItem;
begin
Result := TBtnItem(inherited GetItem(Index));
end;

procedure TBtns.SetItem(Index: Integer; Value: TBtnItem);
begin
inherited SetItem(Index, Value);
end;

procedure TBtns.Update(Item: TCollectionItem);
begin
if Item <> nil then begin
//
end;
end;

{ TBtnPanel }

constructor TBtnPanel.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FBtns := TBtns.Create(self);
end;

destructor TBtnPanel.Destroy;
begin
FBtns.Free;
inherited Destroy;
end;

procedure TBtnPanel.SetBtns(Value: TBtns);
begin
FBtns.Assign(Value);
end;

procedure Register;
begin
RegisterComponents('Samples',[TBtnPanel]);
end;

end.

[Jeferson Oliveira]

John Gallagher escreveu:

> Any suggestions as to how to fix this ?

> TBtns = class(TCollection)

The class TBtns should inherits from TOwnedCollection instead of TColletion:

TBtns = class(TOwnedCollection)

And then adjust your constructor to match the ancestor's create method:

constructor TBtns.Create(Panel: TBtnPanel);
begin
inherited Create(Panel, TBtnItem);
FPanel := Panel;
end;

That's all!

I hope this help.

Jeferson Oliveira
Brazil

[John Gallagher]

"Jeferson Oliveira" <jeferson...@gmail.com> wrote in message
news:466e...@newsgroups.borland.com...

Many thanks. It works now !!